enables pthread

Author: devnexen

Zend/Zend.m4

@@ -212,6 +212,7 @@ AX_CHECK_COMPILE_FLAG([-Wlogical-op], CFLAGS="-Wlogical-op $CFLAGS", , [-Werror]
 AX_CHECK_COMPILE_FLAG([-Wformat-truncation], CFLAGS="-Wformat-truncation $CFLAGS", , [-Werror])
 AX_CHECK_COMPILE_FLAG([-Wstrict-prototypes], CFLAGS="-Wstrict-prototypes $CFLAGS", , [-Werror])
 AX_CHECK_COMPILE_FLAG([-fno-common], CFLAGS="-fno-common $CFLAGS", , [-Werror])
+AX_CHECK_COMPILE_FLAG([-pthread], CFLAGS="-pthread $CFLAGS", , [-Werror])
 
 test -n "$DEBUG_CFLAGS" && CFLAGS="$CFLAGS $DEBUG_CFLAGS"